Four wheel drive road machine



F. D. wlLsoN 1,829,622

Oct. 27, 1931.

FoUn-wHgEL DRIVE ROAD MACHINE:

Filed Oct. 20. 1928 4 Sheets-Sheet l n f" l? D, WgLgQN FOURJJHEEL DRIVE ROAD MACHINE Filed Oct. 20. 3.92.8

4 Shee'hs-Sheer. 2

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Oc.D 279 @3L F. D. WlLsoN 398297622 FH-WHEEL DRIVE ROAD MACHINE Filed OCT.. 20. 1928 4 SheetS-Shee 5 @da 27, 1931. F. D. WALSQN FOUR-\HEEL DRIVE ROAD MACHINE 4 Sheets-Sham '4 Filed Oct. 20

Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE FRED D. WILSON, OF H-ARVEY, ILLINOIS, ASSIGNOR TO AUSTIN MANUFACTURING CO., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS FOUR WHEEL DMVE 'ROAD MACHTNE Application led October 20, 1928.

This A'invention relates to road machines and more in particular to a motor grader propelled by its own power and provlded with a four wheel or dual drive. l

The primary function of the ordinary road 4machine or motor grader to properly malntain the surface of macadam or gravel roads, and since the great majority of such macadam and gravel roads are provided with a relat-ively hard surface, great pressure on the surface tool or blade is necessary and such' pressure can onlybe obtained by borrowing Weight from the frame and assoc1- ated parts through the medium of the blade or tool controlling mechanism. In other Vwords, in order to push the blade ,into the roadway, the frame must be 4pushed upward, and because the frame of the ordinary type of road machine or motor grader is rigidly lsecured to a tractor, the weightborrowed for use at the bladey or surfacing tool is taken from the traction wheels of the tractor. VThis not only reduces the traction or pushing ability of the traction wheels by causing slippage on vthe ground surface, but also causes rapid wear of the tires which are generally made of rubber and are quite expensive.

Furthermore, in the common type motor grader with a single pair of driving wheels at the rear, it is obviously easier for the blade, when positioned diagonally relative to the line of travel and heavily engaged in moving material sidewise, to pull the entire machine off the desired course; i. e. a heavy side load on the blade will cause the front steering Wheels to skid towards the ditch when material is moved in the opposite direction much easier than in a machine having four driving wheels as set out in the present invention, for the reason that the front steering wheels are entirely unassisted by the single rear pair of driving Wheels insofar as holding their course is concerned. Y

In my improved motor grader, the fact" Serial No. 313,730.

the operator and not be Whipped and pushed sidewise b material acting against the face of the bla e or moldboard. My present construction vas a whole, makes the changing of the direction of travel more diiiicult, in that the steering, wheels have more work to do when turning a corner, than on a conventional machine because of the fact that to change the course of travel of the machine, certain of the four driving Wheels must skid slightly on the road surface. This feature in a motor grader is an advantageous one for the reasons heretofore given, since it is obvious that While it is entirely possible for the front Wheels, because of the leverage gained by the long frame and their position at the forward end of it, to cause the necessary skidding of the rear wheels to make a turn, the blade is not positioned so as to have the same leverage, however, and therefore it will withstand a much greater side pressure of material against its face before changing the course of the machine or before it is overloaded, than is possible with the ordinary two wheel drive motor grader.

The location and arrangement of my four driving wheels taken in connection with the method of connecting the tractor and grader frame, lends further stability to the machine While at work in that on the ordinary motor grader the entire tractor weight is carried onthe single pair of drive Wheels which are located at the extreme rear of the long frame and are generally a greater distance from the blade than are the front pair of driving wheels on my present invention.

' In my invention. the tractor weight is on four wheels, which are all drivers and all assist in propelling the machine, .the wheels being arranged in tandem relation, allowing approximately sixty-five percent of the tractor weight to be carried on the front pair of wheels. The front pair of drive .fivheels in the present construction are unaffected by any pressure applied to the blade since the tractor or power plant is pivoted to lthe grader frame at its rear axle housing` and not made rigid as in the ordinary type of grader. This construction permits the front end of the power plant to be always free and unham ered regardless of the kind 'of work done the blade or the amount of pressure app ied thereon. It thus follows that when a portion of the frame weight isborrowed as when' applied to the blade for heavyv work, the tractive eort of the rear pair of wheels only i-s effected and since each front wheel is driven from its respective rear wheel and 'is constantly 'connected 1,0 to it by transmission means, the objectionable skiddin and slipping of the rear wheels is preventediiy the weight on the front drive wheels, the tractive effort of which -is always constant. The frontend of the ower plant, u instead of being carried-by the rame of the grader, as on all previous machines, is carried on its own drive wheels' and axle, which in turn are pivotally connected by heavy rocker beams with the 'rear axle. The term 3 power -plant as used in the specificationv and claims is meant to include an engine or other rime mover and the driving and' support\ means therefor.

e present construction allows the front u end of the power plant to oscillate freely up and down inside the grader frame as no part of its weight is carriedby the frame, and it has no connection with the frame other than a simple adjusting device to keep it in '3 lace between the siderails without -`touching either of them. Whilethe front end of the wer plant is free to rise and/fall on the forward'drive wheels, due t yany u nevenness of the ground. this m ion is not s in anywise communicated to the grader, as

there is no connection between the tractor and the grader except through the rear axle to which the side rails 'are attachedas on all other machines. The entire weight of 4 the' power plant is placed on its own four wheels, and then part 4of the tractor weight which on other machines is carried to the eiframe on the front carrying wheels,

is now placed on the forward drive wheels,

adding considerable extra traction to the wer and eciency of the machine.

Among the objects of my invention are to rovide a road machine or motor grader havmg an elongated frame on the rear end of .Nwhich'is pivotd a four wheel drive mechanism, the front end being supported and steered by a conventional steerable two wheelftruek; 'further to provide a road machine "having four .non-steerable driving wheels, 56 two on` each side ofthe' frame 'and each front axles of a tractor mechanism for permitting their relative movement to control the tenv operation, and such further objects, advantages and capabilities as will later more fully ap ear.

y invention further resides in the combination, construction, and arrangement of parts illustrated in the accompanying drawings, and while I have shown therein a preferred embodiment, I desire it to be understood that the same is susceptible of modification and change, without departing from the spirit of my invention.

In the drawings: Fig. 1 is a view in side elevation of my road machine, two of the driving wheels having been removed to more clearly disclose details of construction. Fig. 2 is a top plan view ofthe road machine. y v Fig.- 3 is a view in vertical cross section taken on the line 3 3 of Fig. 1.

' Fig. 4 is a fragmentary view of the supporting construction for the forward drive wheels. y

Fig. 5y is a view in vertical cross section taken oirthe line 5-5 of Fig..2.

Fig. Gis a view Ain vertical cross section on the line 6-6 of Fig. 2. c

Fig; 7 is a top planview of one of the blade operating mechanisms.

Fig. 8 is a view in vertical cross section taken on the line 8-8 of Fig. 7. Referring more dparticularl to the drawings, my im rove road mac -ine comprises an elongat arch frame '1 provided with frontsteering wheels 2 mounted upon an axle 3 and rear traction and drive wheels 4 and 5. The drive wheels 4 are mounted on the drive shaft v6 of a ward drive w eels 5 are mounted on an axle 8,: the'ends ofwhich axle are connected at each endby means of a'heavy steel rocker :Y 9 to the rear axle housing 10, thus keeping the front and rear drive wheels always in exact alinement. This axle 8 is further attached to the front end of the power plant by heavy multiple leaf springs 11 .so that said Iwheel being driven from its respective rear. power plant'has'a spring sup rt on its own wheel; further to provide a road machine Y or motor grader having an elongated frame with a four wheel drive mechanism pivotally j connected to the rear of the' frame for vertical oscillation, and means .connecting the front of thetractor mechanism to the frame of the grader, said means permitting rela.- tive vertical movement only; further to provide means for connecting the front and rear mounting and in addition is ree to move up and down inside the frame of the grader as any inequalities in the rad surface make such movement necessary, using the rear axle of the tractor or power plant itself as a pivotal point. The leaf springs 11 are mounted on the underside of the rocker beam 9 and are rigidly attached thereto by'suitable anchoring bolts12 and 13. 'A housing 14 is mounted ower plant 7, while the forwithin the rocker arm 9 at its front end 15, this housing further providing a bearing surface for the forward axle. In order to properly drive the forward traction wheels, I provide a sprocket 16 mounted on the hub 17 of the driving wheels 4, and a sprocket 18 on the hub 19 of the forward traction wheels 5. A roller bearing chain 20 engages the sprockets and drives the forward traction wheels, thus providing a dual or four wheel drive for the machine. In order to allow for the vertical oscillation, the springs 11 are attached to and pivoted on rocker arms 21 attached by suitable bracket means 22 to the frame member 23 at the forward end of the power plant. i

In order to prevent side motion of the power plant relatively to the frame, I provide an equalizing device comprising horizontal arms 24 and 25 pivotally connected at 26 and 27 to the frame 23. The member 24 is further pivoted at 28 to an arm 29, the member 25 being pivoted at 30 to the other end of this arm. A diagonal brace rod 31, rigidly secured to the frame of the grader by brace members 31a and 31, is provided with an extension or lug 32 providing a bearing for a pivot 33 for the arm 29.

The front wheels 2 are operated by a steering shaft 34 and steering wheel 35. Located directly behind the front wheels and near the forward end of the machine, is a scarifier 36 mounted upon a frame 37, which frame is pivotally mounted at 38 to the forward part of the machine. This pivotal connection allows for the scarifier to be raised or lowered from contacting relation with the ground. The mechanism for raising or lowering the scarifier comprises arm members 39 and 40 mounted on opposite sides of the machine and connected to the scarifier at its ends. The arm members 40 are operated by suitable gearing 41 mounted on the frame 1 of the machine, the gearing being operated by means of a shaft 42 operated by a suitablesteering wheel.

Located under the arched frame 1 is a triangular frame 43, the forward end 44 of which floats on a vertical pivot pin (not shown). The construction of the forward end of the frame allows for a rotation thereof so as to permit the sides of the blade and frame to be raised and lowered by the operator at will. Rotatably mounted on the under side of the frame 43 is a horizon-tal blade supporting Wheel carrying a grader blade 44, this wheel having a circumferential ange 45a. In order to rotate the wheel 45, the inner periphery of this wheel is provided with an arcuate rack a meshingwith a spur gear (not shown) on a shaft b; This shaft at its upper end is provided with a bevel gear c meshing with a bevel gear d on a shaft c, rotated lfrom the operators station by a hand wheel f.' A pair of pivotal connections -46 to-which are attached vertically extending rods 47, are mounted on a cross arm 48 attached to the under side of the frame 43. These rods 47 are in turn attached at their upper endsto arms 48, which arms are pivotally connected to a shaft 49 extending transverse of the machine. l

Each arm 48a is attached to and made integral with a bell crank 50, and is bifurcated at its lower end for attachment with the rod 47. An arm 51 on the bell crank is pivotally attached at its upper end to a tubular shaped casting 52. This casting is provided at its rear end with a threaded portion 53, which threaded portion is adapted to engage 'the threaded end 54 of a shaft 55. A tube 56 is pressed into the main casting 52 to protect lthe threads and also to provide a support'for a bearing 57 for the shaft 55.

The shaft is reduced at its rearward portion and tits into a housing 59. A sleeve 60 surrounds the reduced end of the shaft within the housing and is provided with a shoulder 61 against which roller hearings 62 and 63 abut. These bearings fit intermediate the sleeve 60 and thehousing 59 and are there held in place. Av closure 64 is attached to the open end of the housing, and provides an abutting-surface for the outer wedge meinand this shaft through its threaded portion yengaging the threaded portion of the casting 52, will either draw this casting towards it,

-or force it away. By means of this operation, the bell crank is either raised or lowered and through its corresponding lever arm will either raise or lower the blade assembly. The housing 59 is pivotally mounted at 67 for oscillation as required by the motion of the bell crank. A spring 68v is connected to the bell crank at 6 9 through a chain 70, the spring being attached 'at it-s other end at 71 to the frame 1. l

In order to provide lateral adjustment of the frame 43 and blade crosswise of the road or transverse of the longitudinal axis of the machine, I provide a hand wheel 72 mounted on an obliquely disposed shaft 73, which shaft is suitably journaled on the frame of A the machine. This shaft is provided with a bevel gear 74 meshing with a bevel gear 75 mounted on a threaded shaft 76. The threaded shaft 76 passes into and through a threaded block or nut 77, which is suitably attached to the rear or base of the triangular frame '43. Whenever the operator rotates wheel 72, he rotates the threaded shaft or inI a horizontal plane about the 1 connection 44 at th front of the machine.

From the above detailed description, it will be seen that I have provided aroad machine ormotor grader of th greatest possible efficiency and rigidity. By means of the four wheel/ drive construction, it is\ sible to proceed over soft ground and ge out of slippery, wet, or otherwise impossible holesand keep 'its place on slippery roads withqut Having thus disclosed my invention, I claim:

1. In a self propelled road grader, in combination'a grader blade, an elongated frame on whichthe blade is adjustably mounted, steering-wheels supporting .the front portion of said frame in front of the blade, a power plant connected to said frame in a position behind the blade, ai pair of ground-engaging drive wheels driven from said power plant and positioned adjacent the rear end of the sliding Ysidewise or. skiddniginto the'ditclhgpowerrplann and a second pair of groundin a manner `totally v'foreign to theold two wheel typ; ...The tractive effort offany moif tor grader is dependent upon the area of contact between the wheels-and the ground and Vthe pressure applied to that area. Naturally,

the greater weight and traction of the four drivingwheels of my construction, means more and* better ground contact, which being spread over four distinct areas separate from each other, so that if one or two wheels run into 'a soft or wet spot there will still be two orthree left on hard ground, and these 'provide traction enough to carry the machine toplaces where a two wheel tractor would stall and have to be dug or towed out.. Also the'forward drive wheels pressing down the softer material as it passes through, provides a solid footing for the rear wheels foll lowing immediately after.) This creates-an per wheel `and ability to work on soft ground and under unfavorable conditions. An-important advantage is that 4by locating the driving Wheels at the rear of the machine with one pair of the driving wheelsspaced forwardly from the other pair and positioned a sub-` stantial amount nearer to `but behind the grader blade than the other pair, an elective inea'ns is provided which oiers a'substantial resistance to the tendencyv of .the side draft to force the machine out of its normal course.

. Further, the distribution of weight on four wheels instead of two, even though total weight is greater, means a less down pressure l a corresponding lessening of the tendency to'v get stuck in soft places, which makes it possible to get out on the` road sooner after a storm or earlier in the Lpringthan with any of the two wheeled machines. Y

By virtue of the four wheel drive construction, the four wheels become positive drive wheels, each one taking' its'- portion 'of `the traction load. This `gives positive tractive elort on four separate and distinct parts of the road surface, eliminating .any1 chanceof the machine being mired down by running@ into a hole or soft place. The freedom of motion that the tractor has in the graden frame enables lit to adapt itself easily to whatever type of road it may be passmgover, and the drive wheels on either side can 'pass over obstructions without deiiecting ;,the course of the grader as a whole. A

e gaging drive wheels also driven from said powcr'plant, said second pair'of drive-wheels beings )aced' forwardly ,from the iirst pair and p .'tioned a substantial amount nearer to the grafer blade than the first pair but behind it, .mas toprovide additional traction, and also providing a substantial resistance to the tendency of the side draft to force the machine out of its normal course.

2. Ina self propelled roadgrader, in combination a grader blade, an elongated Vframe on which said grader blade is adjustably mounted, rotatable means for supporting and steering the front end of the frame and positioned in advance of the grader blade, a

power plant in the rear portion of the frame rear end of the. frame and driven from thel power plant, a second pair of ground-engagingrdrive wheels driven from said power plant and vpositioned in front of the first pair betweenthe rearend of the frame and ythe grader blade, said two pairs of drive wheels being so spaced with relation to the grader blade as to be effective toprevent lateral skidding of the road grader from a heavy side load on the face of the grader blade. M

3. In a self propelled road grader, in combination'a frame 'includin a pair of elongated side members, rotatable supporting and steering means adjacent the front end of said frame, a grader blade adjustably mountedon saidwframe in the rear of said supporting and steering means, a power plant between the rear end portions of-said side members and lll lll

rear end of the power'plant and driven from'v the power plant, a second pair of ground-` engaging drive wheels driven from the power plant andspaced forwardly from said first pairsaid second pair of drive wheels being positioned between the rear end of the frame and the graderblade to effect additional resistance against lateral movement of the road grader from a heavy side load on the face of the grader blade.

4. In a sell:l propelled road grader, in combination an elongatedl frame, rotatable supporting and steering means adjacent the front end of said frame, a grader blade adjustably mounted on said frame in the rear of said supporting and steering means, a power plant in said frame behind the grader blade so that y one end of said power plant moves vertically within said frame but is held against lateral movement with relation thereto, a pair of ground-engaging drive wheels adjacent the rear end of the power plant and driven from the power plant, a second pair of groundengaging drive wheels driven from the power plant and positioned-between the first mentioned pair of drive wheels and the vgrader engaging drlvewheels supporting t e rear end of the power plant and driven therefrom, the front end of the power plant being vertically movable in the frame but held against lateral movement with relation thereto, a second pair of ground-engaging drive wheels driven from the power plant and positioned between said iirst mentioned pair of drive wheels and the grader blade for supporting the front end of the power plant and e ecting resistance against lateral movement of the road grader from a heavy side load on the face of the grader blade, said second pair of drive wheels moving up and down with the forward end of the power plant and acting at all times as ropelling units regardless of the condition ogthe road bed.

6. In a self propelled road grader, in combination an elongated frame, supporting and steering means adjacent the front end of the frame, a grader blade adjustably mounted on the frame rearwardly of the supporting and steering means, a power plant, a. pau' of ground-engaging drive wheels supporting the rear portion of the ower plant and a pair of ground-'engaging rivev wheels supportin the forward portion of the power plant, bot pairs of said drive wheels bein driven from the ower plant, the frame ad]acent its rear end being pivotall connected with the power plant so that the atter may have an oscillatory movement with relation to the frame, the power plant being held at all times a ainst lateral movement with respect to the rame, atleast one pair of said drive wheels being in tractive engagement with the ground at all times whereby a force tending to raise the grader blade, frame and portion of the power plant does not affect the drivin or traction engagement with the ground of: at yleast one pair of drive wheels.

7; A road machine provided with a grader blade, a frame provided with side members carrying said blade, steering wheels at the front of said frame and driving wheels at the rear thereof, a power plant so mounted intermediate said side members thatsaid power plant may oscillate vertically within said frame,'and additional non-steerable driving wheels adapted to carry the front of the power plant and provide additional traction units whereby certain of said drive wheels give tractive eifort regardless of the condition of the road bed, and prevent the frame from being whipped sideways and pulling the machine oil' the desired course due to a heavy side load on the face of the grader blade.

In witness whereof, I hereunto subscribe my name to this specification.

FRED D. WILSON. 

